1. Technical Field
The disclosure relates to wireless communication technologies and, more particularly, to a mobile phone and a status control method adapted for a mobile phone.
2. Description of Related Art
In general packet radio service (GPRS) network, the service area is divided into a number of routing areas (RAs). Each RA is composed of a number of cells. Each cell represents the coverage of a base station. GPRS network uses a pair of finite states machines executed in both the serving GPRS support node (SGSN) and a mobile phone to perform the mobility management (MM) of the mobile phone. The finite status machine has three states: idle state, standby state, and ready state. In the idle state, the GPRS network does not know the existence of the mobile phone. In the standby state, the mobile phone has been attached to the GPRS network, receives, and transmits packet data units (PDUs), and whenever the mobile phone crosses one RA, it is necessary to register to an associated SGSN. In the ready state, whenever the mobile phone crosses one cell, it is necessary to register to an associated SGSN and frequently perform location updates.
To switch from the ready state to the standby state, a ready timer is employed. This approach defines a threshold interval, denoted as T. When a packet is transferred, the ready timer starts to count time in reverse through T time units. If the ready timer has completed the counting and the mobile phone has no data transfer, the mobility management status switches from the ready state to the standby state. However, the ready timer T is a fixed value and frequent location updates waste a lot of power of the mobile phone.